*{
    margin: 0;
    padding: 0;
    border: 0;
  }
  .j{
      height: 725px;
      width: 100%;
      background-color: black;
      overflow: hidden;
  }
  .w{   
        margin-left: 25%;
        height: 100%;
        width: 50%;
        background: url(../img/背景.jpg)no-repeat;
        background-size: 100% 100%;
        overflow: hidden;
  }
  .dljm{
      height: 50%;
      width: 60%;
      margin-top: 150px ;
      margin-left: 20%;
      background-color: white;
      opacity: 0.8;
      border-radius: 5%;  
      font-size: 20px;
      color: #000;
      overflow: hidden;
  }
  .hydl{
      height:50px ;
      width: 200px;
      margin: 0 auto;
      display: block;
      text-align: center;
      font-size: 30px;
      margin-top: 45px;
  }
  .user{
      height: 35px;
      width: 280px;
      background-color: white;
      border-radius: 15px;
      border: 2px solid gray;
      outline: none;
      font-size: 20px;
      text-align:center;
      display: block;
      margin: 0 auto;
  }
  .password{
      height: 35px;
      width: 280px;
      background-color: white;
      border-radius: 15px;
      border: 2px solid gray;
      outline: none;
      font-size: 20px;
      text-align:center;
      display: block;
      margin:0 auto;
      margin-top: 60px;
      overflow: hidden;
  }
  .dl{
    height: 60px;
    width: 80px;
    border-radius: 18px;
    outline: none;
    display: block;
    margin: 0 auto;
  }
